The national midterm Republican sweep may extend to New York’s state Senate.

“I think the GOP will take the Senate as well as the House nationally,” says former Mayor Ed Koch.

“Up in Albany last week, a Senate Republican said to me, ‘I think we’re gonna take this thing,’ ” says Maurice Carroll, director of the Quinnipiac University Polling Institute. “I said, ‘I think you are too.’ And that’s not based on math, because we haven’t been able to do any polling — it’s just what I hear and observe.”

There haven’t been enough resources for comprehensive polls, but should the Republicans take the chamber — there are about 14 races in play, and the GOP needs only to pick up three of those seats — it could, as with President Obama, work in Andrew Cuomo’s favor.

“Dean Skelos, the current minority leader, has been screaming for checks and balances,” says the Siena Poll’s Steven Greenberg. “Most New Yorkers are familiar with the phrase ‘three men in a room.’ Those three are the governor, the Assembly leader, and the Senate president. Is it going to be two Democrats and a Republican, or three Democrats?”

(No chance to have two Republicans. The Assembly is expected to stay firmly Democrat-controlled, with Sheldon Silver still in charge.)

If the senate does flip, a power struggle will likely ensue. Skelos is the leader and wants to be president, but, says one insider, he’s got competition.

“Tom Libous from Binghampton really wants it,” says a source. “George Maziarz from Niagara has expressed an interest. In the Senate, let’s say they flip 32-30. You need 17 senators to vote for the leader. It’s easy to run a coup when you need only 17 votes.”

Still, there’s a chance the Dems could maintain control: Neither Greenberg nor Carroll thinks the recent Aqueduct scandal will have much effect. “We all know,” says Carroll, “that there are certain districts where the Democratic incumbent could be revealed as the illegitimate son of Mao and he’d still get re-elected.”